New organic-inorganic hybrid membranes prepared from chitosan, polyvinylpyrrolidone (PVP), and 1,2-bis(triethoxysilyl)ethane (BTEE) were used for pervaporation separation of methanol-ethylene glycol (EG) mixtures. A semi-interpenetrating network structure at the molecular scale was formed via condensation between chitosan and BTEE in the hybrid membranes. The self-condensation reaction of BTEE took place to form silica nanoparticles. The as-prepared hybrid membranes have denser packing of polymer chains, and higher mechanical strength than their untreated blended counterparts. BTEE hybridization efficiently decreased the membrane swelling in methanol-EG mixture, and enhanced methanol sorption selectivity. Effect of BTEE loading, feed temperature, and feed content on pervaporation performance was investigated in detail. Methanol/EG selectivity increased significantly, whereas membrane permeance decreased, with increasing BTEE loading. The membrane containing 10.4 wt % BTEE has the highest separation factor of 6129 for separation of methanol (6 wt %)-EG mixture at 60 degrees C.